GITC: Always update the gitc manifest from the repo manifest

This way any changes made to the main manifest are reflected in the gitc
manifest. It's also necessary to use both manifests to sync since the
information required to update the gitc manifest is actually in the repo
manifest.

This also fixes a few issues that came up when testing. notdefault
groups weren't being saved to the gitc manifest in a method that matched
'sync'. The merge branch wasn't always being set to the correct value
either.

Change-Id: I5dbc850dd73a9fbd10ab2470ae4c40e46ff894de
diff --git a/subcmds/start.py b/subcmds/start.py
index 188fd7c..940c341 100644
--- a/subcmds/start.py
+++ b/subcmds/start.py
@@ -57,7 +57,6 @@
         print("error: at least one project must be specified", file=sys.stderr)
         sys.exit(1)
 
-    proj_name_to_gitc_proj_dict = {}
     if self.gitc_manifest:
       all_projects = self.GetProjects(projects, manifest=self.gitc_manifest,
                                       missing_ok=True)
@@ -67,7 +66,6 @@
         else:
           project.already_synced = False
           project.old_revision = project.revisionExpr
-        proj_name_to_gitc_proj_dict[project.name] = project
         project.revisionExpr = None
       # Save the GITC manifest.
       gitc_utils.save_manifest(self.gitc_manifest)
@@ -77,9 +75,10 @@
     pm = Progress('Starting %s' % nb, len(all_projects))
     for project in all_projects:
       pm.update()
+
       if self.gitc_manifest:
-        gitc_project = proj_name_to_gitc_proj_dict[project.name]
-        # Sync projects that have already been opened.
+        gitc_project = self.gitc_manifest.paths[project.relpath]
+        # Sync projects that have not been opened.
         if not gitc_project.already_synced:
           proj_localdir = os.path.join(self.gitc_manifest.gitc_client_dir,
                                        project.relpath)
@@ -89,7 +88,7 @@
           project.Sync_NetworkHalf()
           sync_buf = SyncBuffer(self.manifest.manifestProject.config)
           project.Sync_LocalHalf(sync_buf)
-          project.revisionExpr = gitc_project.old_revision
+          project.revisionId = gitc_project.old_revision
 
       # If the current revision is a specific SHA1 then we can't push back
       # to it; so substitute with dest_branch if defined, or with manifest
@@ -100,6 +99,7 @@
           branch_merge = project.dest_branch
         else:
           branch_merge = self.manifest.default.revisionExpr
+
       if not project.StartBranch(nb, branch_merge=branch_merge):
         err.append(project)
     pm.end()